C++中回调函数及函数指针的实例详解

//A类与B类的定义
class A
{
public:
  void Test()
  {
    cout << "A::Test()" << endl;
  }
};

class B : public A
{
public:
  void Test()
  {
    cout << "B::Test()" << endl;
  }
};

//定义类的成员函数指针
typedef void (A::*A_mFun)(void);
typedef void (B::*B_mFun)(void);



int main()
{
  //Code
  A a;
  B b;
  A_mFun pAFun = &(A::Test); //Note:Test成员函数必须为public,否则会报错
  B_mFun pBFun = &(B::Test); //Note:Test成员函数必须为public,否则会报错
  (a.*pAFun)();        //输出A::Test()
  (b.*pBFun)();        //输出B::Test()
  (b.*pAFun)();        //输出A::Test()

  A* pA = &a;
  B* pB = &b;
  (pA->*pAFun)();       //输出A::Test()
  (pB->*pBFun)();       //输出B::Test()
  (pB->*pAFun)();       //输出A::Test(),B*变量可赋值给A*变量


  return 0;
}